首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
1. Effective tools are needed to measure the ‘health’ of rivers at scales large enough to be useful for management. Indicators for assessing the complex of variables that constitutes river health need to be ecologically based, efficient, rapid and consistently applicable in different ecological regions. 2. A large-scale survey of rivers in New South Wales, Australia provided data to test the Index of Biotic Integrity (IBI). The IBI employs the fish-community attributes, identified using regional and river-size data, expected for a river reach of excellent environmental quality. It uses metrics based on species richness, abundance, community structure and the health of individual fish. IBI metrics were established to suit a relatively low-diversity and unspecialized freshwater fish fauna in south-eastern Australia, totalling 55 species. 3. The IBI was able to discriminate between relative levels of environmental quality within a diverse set of stream systems and four presumptive ecological regions. The index was validated by testing the repeatability of scores, and by comparison of IBI scores at eighty sites with an independent measure of potential catchment condition, the River Disturbance Index. 4. Assessments of metric performance showed that eleven of the twelve metrics contributed satisfactorily. One metric based on trophic guild performed poorly and should be deleted from the index. Six other recommendations are made to enhance the performance of the IBI. 5. Results show that, while all large rivers have been disturbed, rivers in the Murray region and those in many coastal montane areas are particularly degraded. 6. The IBI results presented here demonstrate a validated method for large-scale monitoring of river health based on a fish fauna of limited diversity, in the absence of suitable reference sites.  相似文献   

2.
We investigated the influence of mesohabitats on fish communities and on attributes of a multimetric index of fish integrity in the River Meuse basin. Three consecutive 150 m sectors in a Meuse tributary (Ourthe, Belgium), each divided in two or three sub-sections presenting various percentages of mesohabitats (riffles, runs and pools), were sampled by electrofishing. In each sub-section, relative and absolute biomasses of each fish species were estimated. The presence of limnophilic cyprinids was inversely correlated (r 2 = 0.70 and 0.56 for absolute and relative biomass, respectively) with the percentage of riffles. Salmonids preferred runs and their absolute biomass was highly dependent (r 2 = 0.71) on the proportion of this mesohabitat, whereas biomass of limnophilic cyprinids was highly correlated (r 2 = 0.75 and r 2 = 0.82 for absolute and relative biomass, respectively) with pools. A positive correlation (r 2 = 0.58) was established between relative biomass of predators and the percentage of this mesohabitat. An IBI was calculated for the three sectors on the basis of results from the entire Meuse catchment. Scores of most metrics showed low variation among sectors but values of two metrics (% of individuals as tolerant, % of individuals as ubiquitous spawners) were greatest in sector 2, where pools predominated. Further, the lowest IBI score (51/65, integrity class: fair to good) was recorded in sector 2 where pools dominated, while sector 1 (where runs dominated) obtained the highest score (63/65, integrity class: excellent). Sector 3 which has a balanced proportion of riffles and runs obtained an intermediate score (57/65). Considering the response of IBI to the natural variation of mesohabitat proportions, it appears that an accurate sampling requires the prospection of a variety of mesohabitats (with a majority of runs) for the evaluation of river quality.  相似文献   

3.
The Index of Biotic Integrity (IBI) is a measure of fish assemblage health that has been used to assess catchment and stream quality throughout North America. It reflects human perturbations on natural environmental structures and processes. While preserving the ecological foundation of the original North American metrics, we have modified and adapted the IBI to the mainstem Seine River and its major tributaries in France. This successful modification of the IBI to a considerably different fish fauna on a different continent further supports its wider use outside the midwestern United States. Using data collected in 1967, 1981, and 1988–1989 from a total of 46 sites, we show spatial and temporal variation in the Seine as indicated by IBI scores. Statistically significant relationships were found between IBI and catchment area but insignificant relationships existed between IBI and an independent Water Quality Index (WQI) based on water chemistry. Comparisons between the IBI and the WQI indicate that the former is a more sensitive and robust measure of water body quality. Our results demonstrate that the IBI, combined with a statistically designed national monitoring program, would offer a reliable means of assessing spatial patterns and temporal trends in water body improvement or degradation in France. The more primitive fish families in the Basin were affected first by perturbations. These families include all the diadromous species found in the Seine and suggest serious disruption of their life histories.  相似文献   

4.
5.
This paper presents an advanced version of the Index of Biotic Integrity (IBI), a multimetric index to indicate ecosystem health. The multimetric index has been adapted in such a way that it not only indicates overall condition but also specific causes of environmental disturbance. The newly developed index (a) uses data of tolerant as well as intolerant species in a single metric to indicate environmental disturbance, (b) does not require knowledge about species from the literature, and (c) can be applied to artificial landscapes.The metrics proposed here consist of indicator species assemblages that are selected directly for their relationship with an environmental component or specific type of environmental degradation. Thus, each metric indicates a type of environmental concern, which enables conservation practices to be targeted more effectively. Species assemblages for each single metric consist of a combination of species that can be negatively and positively related to environmental disturbances, providing a better indication of stream ecosystem health.The area studied was assumed to be too diverse for one single index. Canonical Indirect-Gradient Principal Component Analysis indicated that the optimal division of subindices based on stream typology was for streams with drainage basin sizes <10 km2 and >10 km2. Pearson Product-Moment Correlations were used to identify relationships between anthropogenic disturbances and the composition and abundance of fish species at impacted as well as undisturbed sites. This index proved to be useful for indicating overall stream ecosystem health as well as local onsite environmental disturbances or the environmental components of greatest concern. This index does require extensive information about measured levels of anthropogenic disturbances with the accompanying composition and abundance of fish species.  相似文献   

6.
7.
高欣  丁森  张远  马淑芹  刘思思  孟伟 《生态学报》2015,35(21):7198-7206
河流生态系统的退化是多空间尺度环境因子作用的结果。探讨不同尺度环境因子及水生生物之间的作用关系,识别影响水生生物群落完整性的尺度问题,是有效开展水生生物保护的基础。基于2009年对太子河流域15个样点的鱼类、河岸带栖息地质量评价,结合遥感影像解译的太子河流域土地利用情况(包括流域尺度和河段尺度),研究鱼类完整性指数(F-IBI)与两种尺度土地利用、栖息地质量参数之间的关系。结果表明太子河上游地区河岸栖息地质量较好,下游地区由于农业用地、城镇用地比例的增加河岸栖息地质量明显下降。F-IBI与自然用地比例呈正相关,与农业、城镇用地比例呈负相关。农业用地对F-IBI的影响体现在流域尺度,而城镇用地在两种尺度上都存在显著影响。相比于农业用地,城镇用地相同比例的增加会导致F-IBI更快的下降。底质、水质状况、人类活动强度是显著影响F-IBI的栖息地质量评价参数。3项参数均随农业和城镇用地比例增加而降低,农业用地主要在流域尺度上对3项参数产生影响,城镇用地主要影响底质和水质状况2项参数,而在两种尺度上的影响相差不大。  相似文献   

8.
We examined the factors controlling fish species richness and taxa-habitat relationships in the Malmanoury and Karouabo coastal streams in French Guiana between the short and long rainy seasons. The aims were to evaluate the environmental factors that describe species richness on different scales and to define the ecological requirements of fish taxa in the two streams at that period of the year. We sampled ten regularly spaced freshwater sites in each stream with rotenone. We caught a total of 7725 individuals representing 52 taxa from 21 families and 6 orders. More taxa were caught in the Malmanoury (n=46) than in the Karouabo stream (n=37). These values augmented by the number of fish taxa caught only by gill nets in a parallel survey fitted very well to a log-log model of fish richness versus catchment area in Guianese rivers. Most of the fish taxa encountered in the Malmanoury and Karouabo streams were of freshwater origin and nearly all the fish species caught in these two small coastal streams were also found in the nearby Sinnamary River with the exceptions of the cichlid Heros severus and the characid Crenuchus spirulus. Moreover, no significant relationship was found between a size-independent estimate of fish richness and distance from the Ocean. Thus, despite their coastal position, the Malmanoury and Karouabo streams contained fish assemblages with strong continental affinities. At a local scale, independently of site size, those with relatively more habitat types harbored a relatively greater number of fish taxa. Canopy cover, water conductivity and bank length were the most important environmental variables for fish assemblage composition at that period of the year. Oxygen and vegetation participated also in defining fish habitat requirements but to a lesser extent. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

9.
D. T. Crisp 《Hydrobiologia》1996,323(3):201-221
This review attempts to assess, as quantitatively as possible, the habitat requirements in fresh water of three common and widespread European salmonid species. Namely: the trout (Salmo trutta L.), the salmon (S. salar L.) and the grayling (Thymallus thymallus L.). Requirements are considered for spawning, incubation and emergence, juveniles and smolts and for adults and spawning movements.  相似文献   

10.
Liu K  Zhou W  Li FL  Lan JH 《动物学研究》2010,31(5):531-538
为促进生物完整性评价法在中国的应用,加强珠江上游广西河池地区河流环境质量监测,该研究以鱼类为研究对象,初步构建了包含21个指标在内的广西河池地区河流基于鱼类的生物完整性评价的指标体系。根据鱼类调查所收集数据,结合历史资料的记录,对这些指标进行筛选和赋值,最终确立了6个指标,用于建立适合广西河池地区河流的基于鱼类的生物完整性指标体系;应用此指标体系对该地区部分河流(河段)进行了评价。评价的结果表明,小环江鱼类完整性为好;红水河、龙江和大环江为一般;刁江为极差。评价的结果与河流受人为干扰的实际情况相吻合,研究构建的评价体系可供河池周边地区使用和借鉴。生物完整性评价是水域环境质量监测的重要手段,为使生物完整性评价更加科学和客观,应加强生物完整性与环境因子之间关系的研究。  相似文献   

11.
The relationships between habitat variables and population densities of masu salmon (Oncorhynchus masou), rosyface dace (Leuciscus ezoe), Siberian stone loach (Noemacheilus barbatulus) and wrinklehead sculpin (Cottus nozawae) were examined by data collected at 55 reaches in forest and grassland streams in northern Hokkaido, Japan. Regression analysis suggested that salmon and dace densities were affected by water temperature (negative for salmon, positive for dace) and structural habitat factors (woody debris for salmon, pools for dace). Salmon density was higher in forest reaches than in grassland reaches, whereas dace density was higher in grassland reaches, suggesting that the removal of riparian forest had raised water temperature and allowed upstream invasions by dace. In contrast to salmon and dace, neither the density of loach nor sculpin differed between the forest and grassland reaches. For their densities, a negative effect of each on the other was most important, suggesting a strong effect of interspecific competition between loach and sculpin on their distributions. However, regression models also suggested that substrate heterogeneity mediated the outcome of their interspecific competition. On the basis of the results, a scenario is predicted for a fish-assemblage change with a typical land-development process in Hokkaido, and the importance of leaving or restoring riparian buffer for conservation and restoration of stream habitat is emphasized.  相似文献   

12.
This study proposes a novel regional sustainability assessment framework for integrated coastal zone management (ICZM). Various ICZM indicators have been developed, but their management insights are not always clear. Our framework integrates three separately developed approaches with an explicit reflection of stakeholders’ values: Satoumi (a Japanese concept of socio-ecological production landscapes, SEPLs), ecosystem services approach (ESA), and inclusive wealth (IW). We suggest that the integration of Satoumi, a uniquely Japanese concept, with the ESA and IW complements each other and increases the effectiveness of all three approaches when applied to ICZM and decision making. Satoumi describes the desired state of a coastal zone. The ESA translates Satoumi into IW and helps explain which changes to ecosystems contribute to the asset quality (i.e., shadow prices). As a sustainability indicator, IW differs from other ecological indicators because it comprises human, natural, and manufactured capital assets and incorporates shadow prices to weigh the contribution of each asset to the present value of social welfare. Shadow prices may capture the quality of capital assets in terms of how much people value them, and can therefore be a direct management target for realizing a desired coastal zone. We propose adding two sustainability criteria, desired state and strong sustainability, to the original IW to make it operational. The framework was tested in Japan’s Seto Inland Sea, and the results were analyzed in depth. Based on the outcomes, we discuss the insights for ICZM and future research. While Satoumi is a Japanese concept, the framework could be applied to other countries where similar SEPLs exist.  相似文献   

13.
Bittner S 《Amino acids》2006,30(3):205-224
Summary. Quinones and amino acids are usually compartmentally separated in living systems, however there are several junctions in which they meet, react and influence. It occurs mainly in wounded, cut or crushed plant material during harvest, ensiling or disintegrating cells. Diffusing polyphenols are oxidized by polyphenol oxidases (PPOs) to quinonic compounds, which associate reversibly or irreversibly with amino acids and proteins. The reaction takes place with the free nucleophilic functional groups such as sulfhydryl, amine, amide, indole and imidazole substituents. It results in imine formation, in 1,4-Michael addition via nitrogen or sulphur and in Strecker degradation forming aldehydes. The formation and activity of quinone–amino acids conjugates influences the colour, taste, and aroma of foods. Physical and physiological phenomena such as browning of foods, discoloration of plants during processing, alteration of solubility and digestibility, formation of humic substances, germicidal activity, cytotoxicity and more occur when quinones from disintegrating cells meet amino acids. The mechanisms of toxicity and the pathways by which PCBs may be activated and act as a cancer initiator include oxidation to the corresponding quinones and reaction with amino acids or peptides. Sclerotization of insect cuticle is a biochemical process involving also the reaction between quinones and amino acid derivatives.  相似文献   

14.
凉水和帽儿山地区低级溪流生境和水质状况   总被引:2,自引:0,他引:2  
为研究不同植被景观土地利用下低级溪流的生境状况和水质差异,对凉水国家级自然保护区红松原始林内和帽儿山国家森林公园境内天然次生林植被和农田背景下各3条溪流生境和水质状况进行调查。对溪流生物特性(悬浮藻、附着藻)和理化性质(温度、混浊度、溶解氧(DO)、pH、NH4^+-N、NO3^-N、PO4^3-P、总氮(TN)和总磷(11P))以及细小颗粒有机物质(FPOM)和粗大有机物质(CPOM))进行测定。研究结果表明,凉水地区原始林溪流的生境状况好于帽儿山地区的次生林,帽儿山地区农田溪流生境最差。原始林溪流具有稳定的溪底生物生活基质,稳水区和急流区均匀分布,稳水区尺度变化大,受淀积物沉降干扰小,河道较弯曲,河岸稳定,河岸植被覆盖度高;次生林溪流以急流区为主,稳定基质相对较差,并受到一定程度的淀积物沉降干扰,河岸尚稳定,有一定程度的人为干扰;农田溪流基质不稳定,受到强烈淀积物沉降影响,渠道化严重,河岸带植被严重破坏。3种景观背景下溪流总磷(11P)、溶解氧(DO)、混浊度、温度、氮磷比值(N/P)(P〈0.05)存在显著差异。原始林溪流NH4^+、DO、TP、TN、悬浮藻浓度和pH较高、附着藻数量较多,温度较低、FPOM和CPOM的数量较少;次生林溪流的NO3^--N、N/P和TDIN较高。 浊度较低;农田溪流浊度、温度、PO4^3--P较高,DO和pH较低,附着藻数量较少。景观尺度上的土地利用对溪流生境具有深刻的影响,同时决定溪流的水质状况。  相似文献   

15.
不同坡向高寒草甸土壤理化特性和微生物数量特征   总被引:1,自引:0,他引:1  
阐明不同坡向草地土壤性质的空间分异格局,为退化草地的精准修复和科学管理提供参考。研究了青藏高原东缘高寒草甸退化草地不同坡向(北坡N、西北坡NW、西坡W、东坡E、东北坡NE、西南坡SW和南坡S)土壤理化性质和微生物数量特征。结果发现:从N→S坡向上,土壤有机质、碳氮比和全氮含量均呈下降趋势,土壤全磷含量和pH值在不同坡向间均无显著差异(P0.05),E坡向全磷含量最高((2.83±0.95)g/kg),NW坡向含量最低((2.07±0.12)g/kg);土壤细菌、真菌和放线菌数量变化呈波动现象,NW坡向的细菌((13.0×10~5±1.0×10~5)个/g)、真菌((14.0×10~3±0.0)个/g)和放线菌((24.0×10~4±1.0×10~4)个/g)数量最低,E坡向的细菌数量最高((85.5×10~5±2.5×10~5)个/g),S坡向的真菌((24.0×10~3±0.0)个/g)和放线菌((209.5×10~4±4.5×10~4)个/g)数量最高;回归分析表明,在E→S坡向上,随土壤含水量、有机质、碳氮比和全氮含量的增加,土壤细菌和放线菌数量均显著降低(P0.05),而土壤真菌数量随含水量、pH值、土壤养分含量的增加略有降低(P0.05)。可见,不同坡向高寒草甸土壤理化特征差异明显,也导致了土壤微生物数量分配格局的不同。  相似文献   

16.
Little is known about the ecology of stream fishes in Zimbabwe and this study investigated fish communities in the Nyagui River basin and is one of the first to examine the relationship between fish assemblages and habitat diversity in Zimbabwe. Fourteen sampling stations were, for convenience, divided into three groups; upper (>1400 m above sea level), middle (1000–14000 m) and lower stations (<1000 m). A total of 24 species were collected, four of which were introduced, and the species composition differed according to the location of the stations. Species that favoured running water and/or rocks were generally absent from the upper stations, reflecting the fact that they were mostly sandy‐bottomed and still. Diversity and relative abundance increased in the mid‐ and low‐altitude stations, which were rockier and faster flowing. Both species diversity and relative abundance increased with the catchment area above each station, which was attributed to increased habitat diversity in larger streams. This view was supported by a strong correlation between habitat diversity and catchment area, and between habitat diversity and species richness and relative abundance. At present, the Nyagui system is relatively unregulated but the Kunzvi Dam, presently under construction, will change this situation and species diversity is likely to decrease owing to the loss of rheophilic species while other groups, notably cichlids and introduced species will increase.  相似文献   

17.
The ideal free distribution assumes that habitat selection is without cost and predicts that fitness should be equal in different habitats. If habitat selection has a cost, then individuals should only move to another habitat when potential fitness in the new habitat exceeds that in the source habitat by an amount greater than the cost of habitat selection. We used isodar techniques to assess the cost of habitat selection. In an experimental landscape, we monitored density, movement, and reproductive success of adult female prairie voles, Microtus ochrogaster, in adjacent paired habitats with low and high cover. We tested the following hypotheses: (1) adult female prairie voles exhibited density-dependent habitat selection; (2) the cost of habitat selection was density-independent. Habitat quality based on population density and fitness of adult females was higher in high cover habitats. Net movement was from low cover to high cover habitats. The results indicated that adult female prairie voles exhibited density-dependent habitat selection. Furthermore, there was a significant cost of habitat selection, and the cost was density-independent.  相似文献   

18.
This study was designed to characterize benthic communities and physical habitat in both an urban (Kirker Creek) and residential (Pleasant Grove Creek) stream in California in late spring of 2006 and 2007. Concurrent water quality evaluations, physical sediment parameters, pyrethroids, bulk metals, and SEM/AVS ratios were also measured during both years of this study. The relationship of various benthic metrics to physical habitat metrics, pyrethroids, and metals was evaluated for each stream using stepwise multiple linear regressions with both years combined for each stream, as well as both years and both streams combined, to increase the statistical power for determining significant relationships. Physical habitat was determined to be poor in each stream during both years of sampling. More than 100 benthic taxa were reported annually for both streams based on 2006 and 2007 sampling. A significant result from the stepwise regression analysis combining data for 2 years across both streams is that when habitat metrics and to a lesser degree metals are considered in the statistical models pyrethroids do not display any significant relationships to the benthic metrics. In summary, it is apparent from this analysis that the health of benthic communities in both streams is primarily affected by habitat metrics.  相似文献   

19.
Human activities have led to declines in stream functioning and stream restoration seeks to reverse this trend. Longwall coal mining, an underground full‐extraction method, can cause surface subsidence, affecting streams by creating a series of deep pools that trap sediment, reduce habitat diversity, and impair macroinvertebrate and fish communities. Mining effects on streams must be mitigated to maintain the functions, values, and foreseeable uses of streams. Gate cutting is a procedure that alleviates pooling by reestablishing the stream grade, accompanied by procedures that stabilize the channel, restore substrates, and enhance in‐stream and riparian habitats. We evaluated effectiveness of gate cuts at restoring streams affected by subsidence pooling at 18 independent restoration sites over two mines in southwestern Pennsylvania, U.S.A. At each site, sampling stations were established to monitor effects of mining subsidence and its restoration on macroinvertebrates, fish communities, and habitats. We tested for effects of sequential interventions (subsidence and restoration) on biological and habitat variables in a replicated before–after design, controlling for potentially confounding temporal effects (sample month and antecedent effective precipitation). All biological indices and substrate‐related habitat indices declined following subsidence but improved following restoration. Macroinvertebrate indicex and taxa richness, substrates, and riparian vegetation continued to improve with time following restoration. Whereas other studies have concluded that biological communities may take many years to respond to restoration, these results indicate that where macroinvertebrate and fish communities are altered by subsidence pooling, they can be effectively restored using gate cuts to pre‐mining levels within relatively short time periods.  相似文献   

20.
The present study aims to determine biological fish production of a lagoon and relate this to the commercial fisheries yield. The fish community of an estuarine lagoon in the west coast of Portugal was sampled between November 1998 and November 2000 to estimate the production ecology of the community, including somatic production, population size, species richness, species diversity, and biomass. Using the Allen curve method of determination, the total annual fish production of all fish species in the lagoon was calculated at 90.3 tonnes or 2.1 g m−2 year−1 in the first year and 106.7 tonnes or 2.5 g m−2 year−1 in the second year. The marine seasonal migrant species, sardine, Sardina pilchardus, which colonises the lagoon during the juvenile period of its life stages, produced more than 35 tonnes in each year and accounted for >39 and >33%, in the first and second year respectively, of the total fish production in this lagoon. Sardine was numerically more abundant (18,217 specimens) but due to their small size contributed only 13% to the total biomass. Sardine was thus the most important fish species in terms of the consumption and production processes of the whole fish community in this system. Commercial fisheries’ records indicate that approximately 300 tonnes per annum of fish are taken from the lagoon, which corresponds to three times more than the estimated production in the lagoon. Thus, if it exists, the sustainability of the fishery appears to depend on the immigration of fish from the adjacent coastal area and it is questioned whether the fishery is sustainable in the long-term. The findings indicate that careful and effective management of the lagoon is required to ensure a long-term healthy aquatic environment and sustainable catches in the future.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号